Evaluation of Pre-Amorphized Layer Thickness and Interface Quality of High-Dose Shallow Implanted Silicon by Spectroscopic Ellipsometry

We have applied spectroscopic ellipsometry (SE) to measure pre-amorphized layer thickness and interface quality of high-dose shallow implanted silicon as a non-destructive, in line implant monitoring technique. The thickness of pre-amorphized layers formed under various ion implantation conditions was estimated by SE, high resolution Rutherford backscattering spectroscopy, and cross-sectional transmission electron microscopy, and the values from the different techniques were compared. The amorphized layer thickness measured by SE showed larger thickness values than those from other techniques, implying the thickness estimated by SE includes the thickness of the heavily-damaged region near the amorphous-crystal interface where “end of range” defects exist. The thickness of the amorphous layer and heavily-damaged interface layer formed by helium in plasma doping and shallow junction implantation can be monitored by in line SE.